Heating system.



H. LEMP.

HEATING SYSTEM.

APPLICATION FILED MAY 10,1910.

Patented Nov. 1, 1910.

t to .7 Invent-pr? Hermann Lemp.

EMVVVVVV.

W|tnesss M UNITED' STATES PATENT OFFICE.

HERMANN LEMP, OF LYNN,v MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

HEATING SYSTEM.

Specification of Letters Patent.

Patented Now 1, 1910.

To all whom it may concern:

Be it known that I, HERMANN LEMP, a citizen of the United States,residing at Lynn, in the county of Essex, State of Massachusetts, haveinvented certain new and useful Improvements in Heating Systems, ofwhich the following is a specification.

The present invention relates to heating systems having boilers whereinwater is converted into steam by passing a current of electricitythrough it.

The object of the invention is to provide a steam generating or heatingsystem wherein steam will be quickly'and efficiently generated as neededto supply the requirements.

in carrying out my invention, a current of electricity is caused to passdirectly through the water, as distinguished from heating the walls ofthe containing boiler or vessel, and, as the steam is generated, it iscarried otl throu h one or more suitable distribution pipes. %Vater issupplied to the vessel under pressure from a service main or pump, asthe steam is drawn off, and in proportion thereto under the control of asuitable regulator.

The boiler receives a current of electricity from a suitable source, forexample from a trolley wire or from the third rail of an electricrailway system. It is to be understood 'that the boiler can be usedunder any conditionwhere one is needed, but it is of special value onelectric locomotives for supplying heating fluid to the coils orradiators on connected railway cars or coaches. In the presentembodiment water is forced into the boiler by a motor driven pump, underthe control of a ball-float located in a water column which is piped tothe boiler. Properly connected to the water column are electricalcontacts which cotiperate with the float. When the water level fallsbelow a certain point, the float connects the contacts, thereby closingthe motor circuit and starting the pum When a certain height of water isreac led, the circuit is broken and the pump is stopped. Steam or heatedliquid is carried oil from the top of the boiler through a suitabledistribution pipe. Connected to this pipe is a die hragm regulator whichopens a switch w ien the pres sure becomes abnormal, the said switchcontrolling the heating circuit. This switch is also ofpened by means ofa suitable con troller i the water level falls below a predeterminedpoint.

The boiler shell is provided with suitable insulating material for abouttwo-thirds its height. Located in the bottom of the in sulating shell isa pool of mercury, into which the feed water pipe projects, the saidpipe extending through the cover to a point near the bottom of theboiler. The feed pipe is insulated from the cover and water, and extendsinto the mercury, so as to pre vent corrosion of the electrodes. Sincethe lower end of the pipe enters the mercury, the latter afibrds acontact area equal in cross-section to that of the column 01'' water. Bythis arrangement is insured a roper dis tribution of the electriccurrent t rough the water and the resistance will be approximatelyconstant, the only variation being due to the fluctuation in the heightof the fluid in the boiler above its insulated lining.

in the accompanying drawing, Figure 1 illustrates oneembodiment of myinvention partly in section and partly in elevation, certain of theparts being diagrammatically shown and. Fig. 2 shows a modification ofone part oil-the apparatus.

Referring to the drawing, 1 represents a plunger pump of any well knownconstrue tion, driven by a series wound electric motor 2, and arrangedto supply water to an electric boiler 3, its inlet and outlet valvesbeing shown in dotted lines. Water for the boiler is contained in a tank4. and is fed to it by means of pipes 5 and 6 which are connectedtogether by a hose of rubber or other suitable insulating material 7..The hose ,effectively insulates the pump 1 from the boiler 3, therebyeliminating all danger due to electric shocks. The resistance of thecolumn of water in the hose is so great that there is no danger ofcurrent flowing through it to the pump casing. Between the feed pipe 6and the hose 7 is a check valve 8 opening toward the boiler, so that thehot water and steam cannot be forced from the boiler into the hose andruin it".

Current for heating thewater is supplied from a source which ispreferably a trolley wire or third rail 10, said current passin throughthe wire 11, feed water pipe 6, p00

of mercury 18, boiler casing 3 and water therein to the negative side ofthe line 12-, and the ground connection 13.

Connected to the wire 11 is a motor circuit 14, manually controlled by aswitch 15. The motor circuit is connected to a water level actuatedregulator 16. A relay-switch conductor 17 for the heating circuit is'also connected to the circuit wire 11. The passage of current throughthe conductor is controlled by a regulator sensitive to boiler pressureand including a switch operated by a diaphragm. WVhen the circuit isbroken it cuts out a relay solenoid magnet and releases a switch in theheating circuit, thereby cutting off the current from the boiler 3.

The water passing through the pipe 6 is forced into and through a poolof mercury 18 in the bottom of the insulated shell, a sufficient spacebeing left between pipe 6 and insulating lining 19 for this purpose.

The greater portion of the feed pipe 6 located in the boiler 3 iscovered with an insulating tube 20, the upper portion of which isthreaded into a cover 21. The lower end of the tube projects slightlyinto the mercury 18 or at least makes contact therewith. Thisconstruction thoroughly insulates the pipe 6 from the cover 21 and thewater, the mercury protects it from the water in the boiler shell 3, andsaid mercury serves as an electrical conductor between the pipe and thewater. By introducing the pipe from the top the mercury is preventedpassing through the tube back to the pump when the system is idle.

It is best to make the liquid slightly con ducting by using a smallquantity of sodium carbonate which should remain sensibly the same, thefresh water entering redissolving the amount of salt liberated throughevaporation.

The inner surface of the boiler shell. as mentioned before, is linedwith suitable insulating material 19 for about two-thirds of its height,and since the feed water pi )e 6 is insulated from the water in theboiler, and the shell is insulated for about twothirds of its height,the current is forced to pass throughithe mercury to the water and thusheat it.

The mercury serves as an anode or terminal for the electric source fromwhich the current flows into the liquid to be heated, and ofiers acontact area equal in cross-section to the water, which properlydistributes the electrical current through it. As the electric currentpasses through the liquid it carries with it and deposits mercury on thecathode or boiler shell 3.

When a direct current is used, and the mercury deposit becomessufiiciently heavy, it will drop from the shell and fall through -thefluid or electrolyte, and rejoin the mass of mercury "forming the anode.With alternating currents the deposition of mercury will be slight.

The heated fluid passes into the discharge pipe 23 for properdistribution. In the discharge pipe is a relief valve 24, said valvebeing set to open at a predetermined pressure, and an adjustablereducing valve 25.

Mounted on the feed pipe 6 is a manually controlled valve 26- which isused for blow ing off the boiler salts or sediment when an undesirableamount has accumulated therein.

\Vhen using boilers of this type in a heat.- ing system, it is importantto maintain the pressure and temperature of the heating fluid constantor substantially so, irrespective of the change of load. This isaccomplished by a regulator responsive to the pressure changes, andcomprising a casing containing a diaphragm 28, that is opposed by acompression spring 29. The movement of the diaphragm automaticallycontrols a switch 30 in the relay circuit. So long as the pressure underthe diaphragm is less than a certain amount, the switch remains closed,but when it rises above a certain amount, the switch opens andinterrupts the said rela circuit 17. When the switch 30 is opened, itbreaks the relay circuit and allows the armature of the relay magnet 31to drop and open the heating circuit at the switch 32. The heatingcircuit is connected to the trolley wire or third rail by a sliding shoe33 and is also controlled by a manually operated switch 34. In boilersof this type, when used for the purpose intended, it is necessary tohave an automatic water-feed regulator. This regulator in the presentembodiment comprises a column 16 connected to the boiler 3 by pipes 35and 36. These pipes permit the water from the boiler to circulate freelythrough the column. \Vhen the water rises or falls in the boiler 3, itrises and fails a corresponding distance in said column. A. ball float37 is controlled by the movement of the water, which float, if loweredto the level of the insulated electrical contact 40 and the upper end ofthe contact 41, contacts therewith and closes the motor circuit 14, thecurrent passing through the ball 37 to the ground connection 13, therebycompleting the circuit. The contact l1 is connected to the ground by theconductor 14. When the circuit is closed, the pump motor 2 starts intooperation and forces water into the boiler 3 until it rises to itsmaximum height, when the circuit will be broken by the separation of theball from the contacts and the motor stopped. A ball or float 42connects the insulated contact 43 with the lower end of the contact 41and completes the circuit 17 except when the water level fallssufiiciently to lower the ball away from said contacts.

: In Fig. 2 a modification is shown in which E a relay magnet 44 isplaced in the pump motor circuit and controls the switch l in thecircuit 17. The switch is shown in its closed position with the ball 46floating above the contacts. The spring 4:7 tends to keep the switchclosed.

Briefly stated the action is as follows: The boiler 3 is supplied withwater from the pinup which receives its supply from the tank 4. Thewater is discharged into the mercury 18, passing through and remainingabove it owing to its lesser specific gravity. \Vhen the water isconverted into steam or is sutliciently heated, it passes through thedischarge pipe 33 to the distributing system. ben the pressure becomesexcessive, the diaphragm 28 opens the switch 30 in the relay circuit 17and the switch 32 in the heating circuit opens, thereby cutting oil thecurrent. in said heating circuit. It the water in the boiler rises abovea certain height, it causes the ball 37 or float 46 to interruptthecircuit between the adjacent contacts, thereby shutting down the pump.

By arranging the parts of the boiler as described there is no danger ofarcing between the positive and negative electrode even when relativelyhigh voltage is em ployed on the system, as 500 volts for example. Tostate the matter in another way, the positive and negative poles arewell insulated and the distance which an arc would have to travelispurposely made so long that it could not be maintained, thus safeguarding the apparatus. This is an important feature since liquid to beheated might oiraccountof impurities or other foreign matter become a,very good conductor, or the liquid supply might temporarily fail whollyor in part. under which circumstances. the are would jump between theelectrodes it the distance was relatively short.

To avoid any possibility Oi injury to the apparatus by overheating orburning should the water supply fail due to any cause and pressurebeinsufficient to open the switch 30, the ball or float. 42 or the switch45 each controlled by the water level is provided. These devices furthersafeguard the equipment by opening the circuit 17 and the heatingcircuit controlled by it when the water level falls below apredetermined point. I

By using a pool of mercury through which the current mustpass beforeacting on the liquid, I am able to prevent the positive electrode fromwasting away and the particles thereof being carried off with the vaporgenerated. The mercury after it enters the solution of the electrolyteis de posited on the negative pole (the wall of the vessel above theinsulating lining) in metallic form and after a suflicient amountaccumulates it will return to the pool (the positive pole) by gravity.

In accordance with the provisions of the patent statutes I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means.

\Vhat I claim as new and desire to secure by Letters Patent of theUnitedStates, is

1. In combination, a vessel containing a liquid to be heated that is arelatively poor conductor of electricity and also a body of fluid thatis a good conductor thereof, means for conveying a current ofelectricity to said body of fluid. and means for receiving said currentafter it has passed through said body and also the liquid.

2. In combination, a vessel containing a liquid to be heated and also abody of inercury, means for conveying a current of electricity to themercury, and means for receiving said current after it has passedthrough the mercury and also through the liquid.

3. In combination, a vessel containing a liquid to be heated and also abody of fluid that is a good conductor of electricity, means forconveying liquid to the vessel and vapor or liquid therefrom, aconductor for supply ing current to the body of fluid, and a conductorreceiving said current after it has passed through the body of tluid andthe liquid.

4:. In combination, a vessel containing a liquid to be heated and also abody of fluid whose specific gravity is greater than that of the liquid,a means for supplying liquid to the vessel under pressure, a conduit forconveying vapor or heated liquid from the vessel, a conductor thatsupplies current to said body of fluid, a conductor receiving thecurrent after it passes through the body of fluid and the liquid. adevice for controlling the supply of liquid to the vessel, and a meansfor regulating the supply of current through the conductors.

5. In combination, a vessel containing a liquid to be heated and also abody of mercury, conduits conveying liquid to the vessel and liquid orvapor therefrom, a pump that is normally in operation to continuouslysupply liquid to the vessel, a regulator for the motor that is sensitiveto change inlevel of the liquid in the vessel, conductors for conveyingcurrent to the vessel and receiving it after it has passed through themercury and the liquid, and a regulator for controlling the passage ofcurrent whichis; sensi tive to a condition of the liquid being heated.

6. In combination, a vessel having an'in sulating lining covering aportion of its inner wall and containing a liquid to be heated and alsoa body of good conducting material, an electrode that makes contact withsaid body and is insulated from the liquid, a conductor conveyingcurrent to the electrode, and a second conductor conveying current fromthe vessel after it has passed through the said body and the liquid. 7

7. In combination, a metallic vessel hav ing an interior lining for aportion of its inner surface, and containing a body of 'me-rcury andalso liquid to be heated, an electrode that is insulated from the liquidand has one end submerged in the mercury, means for supplying liquid tothe vessel and conveying it therefrom after being heated, conductors forconveying current to the electrode and receiving it from the vesselafter it has passed through the mercury and the liquid, and means forregulating the flow of current through the conductors.

8. In combination, a vessel containing liquid to be heated that is arelatively poor conductor of electricity, and also a body of fluid thatis a good conductor thereof, and is also'below the liquid and in contacttherewith, an electrode that enters the said body and is in electricalcontact therewith, the

cross-sectional area of the electrode beingless than that of the body,means for supplying liquid to the vessel and conveying it away afterbeing heated by the current, and means for supplying current to theelectrode and receiving it after it has imparted heatto the liquid. I

9. In combination, a vessel containing liquid to be heated and also abody of mercury, means for supplying liquid to the vessel by forcing itthrough the mercury, an outlet for the vessel, means conveying currentto the mercury, and means receiving said current after it has passedthrough the mercury and the liquid.

10. In combination, a vessel containing liquid to be heated and also abody of mercury, a feed pipe which-enters the body of mercury so thatthe liquid flowing therefrom must pass through the mercury, a means forconveying current to the feed pipe, and means receiving current after itpasses through the feed pipe, mercury and iquid.

11. In combination, a vessel containing liquid to be heated that is apoor conductor of electricity and a body of fluid that is a goodconductor thereof, a conductor that serves both as a means for conveyingcurrent and a supply of liquid, an outlet for the vessel, and a meansreceiving current after it has imparted heat to the liquid.

12. In combination, a closed vessel containing liquid to be heated, anelectrode that extends throu h the principal portion thereof and is insuated therefrom, a pool of mercury in which one end of the electrode issubmerged to prevent it from wasting away due to the action of thecurrent and also to afford an enlarged area for conveying current to theliquid, and a means for conveying current from the vessel after it hasheated the li uid.

13. In com ination, a vessel containing a liquid to be heated and also abody of mercury, means for supplying liquid to the yessel underpressure, a conduit for conveying vapor or heated liquid from thevessel, conductors for conveying current to the vessel and receiving itafter it has passed through the liquid and the mercury, and a regulatorfor controlling the passage of current which is sensitive to change inthe level of. the liquid.

14. In combination, a vessel containing liquid to be heated and also abody of mercury, a pump for supplying liquid to the vessel underpressure, an electric motor for driving the pump, a conduit forconveying vapor or heated liquid from the vessel, conductors forconveying current to the motor and to the vessel and receiving it afterit has passed through the liquid and mercury in said vessel and aregulator for controlling the passage of current through said conductorswhich is sensitive to change in the level of the liquid.

In Witness whereof, I have hereunto set my hand this seventh day of May,1910.

HER-MANN LEMP. Witnesses:

JOHN A. MoMANUs, Jr., WILLIAM H. PRATT.

